Beta Altitude 1.5

- Overhaul 80 % of global textures
- Overhaul all firs normals, colors and imposters
- Overhaul all meshes errors
- Overhaul 70 % of meshes for optimisation
- Overhaul ambiance lighting
- Add 5 km of asphalt with 2 tunnels and a reservoir
- Add the bus shelter (no collision for the moment, this mesh is a charpenter project and have no simplifications)
- Remove the old space hole and create a new one...

This is the official released version.
The loop around the mountain is closed, 12 km of asphalt road and 6 km of dirt road.
* Improvements since v0.7 :
- Add escapes for jumps.
- Add 6 km of asphalt road with cliffs and tunels.
- Add 2.5 km of dirt road in forest.
- Add an arena.
- Add a surprise end of the track!
- Ambient sound modified.